engleski

Phase-field solution scheme for fracture in heterogeneous microstructure

The phase-field approach to fracture modeling regularizes the sharp crack discontinuities with a scalar damage field whose value differentiates between the broken and unbroken material states. Thus, the implementation complexity is significantly reduced by eliminating the need to numerically track the discontinuities of the displacement field, inherent to the discrete crack modeling methods. Moreover, it has been demonstrated that the phase-field approach is successful in handling complex fracture processes even in three dimensional settings. However, it can be computationally very expensive. This contribution presents an implementation of the phase-field model of brittle fracture within the commercial finite element software Abaqus. The problem of computationally demanding fine loading incrementation required to obtain an accurate solution is tackled through a staggered iteration scheme coupled with an appropriate convergence control setting. Thus, by taking advantage of the Abaqus automatic time incrementation and its numerical efficiency, an accurate solution can be obtained for a moderate time step. Along with the model verification on a simple homogeneous material behavior example, a porous microstructure exhibiting crack nucleation and complex crack paths is analyzed. Detailed results in terms of robustness, accuracy and computational cost are presented. The proposed implementation demonstrates an improvement in the computational efficiency compared to the previous works.

Phase-field Fracture, Abaqus, Staggered, Convergence control, Heterogeneous Mictrostructure

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